1. Field of the Disclosure
Example embodiments of the present disclosure relate generally to a laser scan unit for an image scanning device, and more particularly to a housing for a laser scan unit having a metal construction and simplified mounting mechanisms for the optical components of the scan unit.
2. Description of the Related Art
Multibeam and single beam laser scanners typically include a housing for holding the scanner's optical components that is constructed from a thermoplastic. Such thermoplastic housings disadvantageously shrink non-uniformly during the molding and subsequent cooling process in the manufacture of the housing. The inconsistencies associated with the molding and cooling of these critical parts creates two primary issues.
First, part-to part dimensional variation of features for mounting sensitive optical components, such as mirrors and lenses, creates the need for assembly adjustment mechanisms during production as well as additional components. Second, during normal operation of electrophotographic printers, the fuser assembly, the laser scanner motor and other printer components and assemblies may create heat. As the thermoplastic housing heats, it expands thermally at two different coefficient of expansion based rates: parallel to the flow and fiber direction of the plastic during injection molding, and perpendicular to the flow and fiber direction of the plastic. The complex shape and features of the housing design, with a multitude of flow disruptions and directions, does not expand uniformly when heated, causing the part to warp or change shape along with the absolute expansion of the housing. This change of size and shape of the housing, which locates the critical laser pointing and focal elements, creates print quality issues associated with change of spot size and location of the laser image on the pc drum, primarily color to color registration of the four color planes (CMYK).
Based upon the foregoing, a need exists for an improved laser scan unit for an imaging device.